Protecting wildlife populations by looking at individual health

Wildlife health assessments provide important information for managing threats to endangered species. In our review, we wanted to understand the trends in study design and methods, and suggest future directions to improve conservation efforts. We found that these assessments are similar  to those at a general health check at the doctor: a physical examination, blood analysis, and some weight and height measurements. A faecal analysis is also at the top of the list. But performing these procedures in the wild is not that easy, especially when the target species is very difficult to find. 

We, therefore, wanted to know: Are researchers from different countries collaborating to study threatened species, and are they sampling enough individuals and in the right locations, to best understand how to protect and manage them? 

To answer these questions, we explored 261 studies on wildlife health assessments in the field over the last 30 years. We learned that most studies sampled fewer animals than statistically recommended, which may be related to restrictions in funding, permits, and logistics. Low sample sizes may reduce the accuracy of reference ranges determined for physiological parameters in individual species. We were surprised to find that countries with high and threatened biodiversity were greatly underrepresented. Almost half of the studies were conducted by researchers based in the U.S., and most of the time within their own country. European and Australian studies were also well represented. On the other hand, Asian, African, and South American countries were scarce. We found that international collaboration was rather uncommon, and that it was established by only one third of the researchers. International collaborations are especially important for protecting migratory animals, which often cross jurisdictional boundaries. 

Based on our review, we provided a conceptual framework to improve design, data acquisition, and analysis, as well as species conservation planning and management implications. The framework was based on our findings and the existing guidelines for species conservation. We were especially interested in highlighting the following points: (1) What background information is needed before starting a health assessment study; (2) What logistics and resources should be considered; (3) What data and how many samples should be collected and analysed; and (4) How can this information benefit conservation management? 

We advocate boosting conservation efforts where they are most needed, and establishing more strategic international collaborations. We suggest following standardized approaches, as well as examining enough individuals to draw impactful conclusions. This way, informed decision making can support healthy wildlife populations and ultimately protect biodiversity.

Further reading:

Deem, S. L., W.B. Karesh, & W. Weisman. 2001. Putting theory into practice: wildlife health in conservation. Conservation biology 15: 1224–1233. 

IUCN (International Union for Conservation of Nature) – SSC (Species Conservation Planning Sub-Committee). 2017. Guidelines for species conservation planning. Version 1.0. Gland, Switzerland.

Kophamel, S., B. Illing, E. Ariel, M. Difalco, L.F. Skerratt, M. Hamann, L.C. Ward et al. 2021. Importance of health assessments for conservation in non-captive wildlife. Conservation biology. doi: